1. Field of the Invention
The invention generally relates to an infant flotation device for use in a marine environment.
2. Description of the Related Art
Flotation devices for adults and children in a marine environment typically take the form of a life preserver or jacket that is worn by the user for the purpose of maintaining the user at the surface of the water in the event that the user falls into the water. This type of life preserver does not work well for small children or infants weighing approximately 20 pounds or less. Infants and children weighing less than 20 pounds are likely to be unable to maintain an erect position and keep their head above the water when using this type of life preserver. The smallest life preserver approved by the United States Coast Guard is only rated for children over 20-22 pounds.
Several types of devices have been invented for use as flotation devices for infants and children weighing approximately 20 pounds or less. These devices are typically modified infant carrier or automotive safety seats that secure the passenger within the seat using one or more straps or harnesses, as is known in the art.
One type of seat relies on parts made from a buoyant material such as foam. For example, the devices disclosed in U.S. Pat. No. 7,008,281 and U.S. Patent Application No. 2005/0101202 consist of a flotation enhancing structure made from buoyant material, such as foam, that can be attached to an existing infant carrier or safety seat. U.S. Pat. No. 6,589,089 and WO0202398 both disclose seats having one or more parts made from or filled with buoyant foam. These types of seats all rely on the relative placement of buoyant material to maintain the seat and the passenger in an upright position in the water such that the passenger's head is above water.
Another type of seat incorporates a stationary ballast or weight into the seat to provide self-righting movement and stability to the device. For example, the seats disclosed in U.S. Pat. Nos. 4,725,253, 5,514,020, 6,296,305, 6,863,017, 6,715,830 and 6,702,380 include a carrier seat or safety seat modified with flotation material attached to the frame of the seat or hollow plastic housing to provide buoyancy. A stationary ballast weight can be situated below the seat's center of gravity to maintain the seat in an upright position in combination with the placement of buoyant material.
Yet another type of seat includes a ballast cavity that can be filled with a ballast material such as sand or water to provide stability to the seat. For example, U.S. Pat. No. 6,036,563 discloses a floating chair comprising a hollow body member to provide buoyancy and a separate hollow chamber that can be filled by the user with sand or water. U.S. Pat. No. 6,482,060 discloses an infant safety seat having parts made from buoyant material and ballast ports in the base of the seat. When the seat enters the water, water enters an empty space through the ballast ports. The ballast water provides stability to the seat in the water and maintains the seat in an upright position.
Flotation seats that incorporate the use of a ballast weight or chamber provide stability to the seat in the water and help to maintain the seat in an upright position in the water. Some seats, such as those disclosed in U.S. Pat. Nos. 6,296,305 and 6,482,060 incorporate a feature, such as a handle or canopy, in addition to the ballast weight into the seat to induce the seat to move into an upright position in the water if the seat enters the water such that the seat is not in an upright position. However, these seats rely on stationary ballast weights and features which may affect the rate at which the seat moves into an upright position in the water depending on manner in which the seat enters the water. The rate at which the seat enters an upright position in the water is critical as exposure of the passenger's airways to water leading to lack of oxygen or drowning may occur if the seat is maintained in a non-upright position for some length of time.